TW202225274A - Polyimide composition, adhesive film, laminate, coverlay film, copper foil with resin, metal-crad laminate and circuit board - Google Patents

Abstract

The present invention provides a polyimide composition which uses thermoplastic polyimide and can form a resin film with a low dielectric loss tangent and excellent adhesion. A polyimide composition comprises (A) thermoplastic polyimide and (B) polystyrene elastomer resin with an acid value of 10 mgKOH/g or less, and with respect to 100 parts by weight of (A) component, the content of (B) component is in the range of 10 parts by weight or more and 100 parts by weight or less. The thermoplastic resin layer obtained by forming the polyimide composition into a film, after being dehumidified under the constant temperature and humidity conditions of 23 DEG C and 50% RH for 24 hours, has a dielectric loss tangent (Tan[delta]) as measured by split post dielectric resonator (SPDR) at 10 GHz of 0.0020 or less.

Description

Polyimide composition, resin film, laminate, coverlay, copper foil with resin, metal-clad laminate, and circuit board

The present invention relates to a polyimide composition useful as an adhesive in circuit boards such as printed wiring boards, resin films, laminates, cover films, copper foils with resin, metal-clad laminates, and circuit boards.

In recent years, with the development of miniaturization, weight reduction, and space saving of electronic devices, flexible printed wiring boards (Flexible Printed Circuits) that are thin, lightweight, flexible, and have excellent durability even when repeatedly bent , FPC) increased demand. FPC can realize three-dimensional and high-density mounting even in a limited space, so its use is expanding to electronic equipment such as hard disk drives (HDD), digital video disks (DVD), mobile phones, etc. Wiring, cables, connectors and other parts of the moving parts.

In addition to the above-mentioned densification, the performance of equipment is also progressing, so it is also necessary to cope with the increase in the frequency of transmission signals. In information processing or information communication, in order to transmit and process large-capacity information, efforts are being made to increase the transmission frequency, and the printed circuit board material is required to reduce transmission loss by thinning the insulating layer and improving the dielectric properties of the insulating layer. In the future, for the insulating layer (including the adhesive layer) constituting the FPC, it is increasingly required to reduce the transmission loss and cope with the increase in frequency. Regarding the improvement of the dielectric properties of the printed circuit board material, an adhesive composition containing an acid-modified polystyrene elastomer resin, a carbodiimide resin, and an epoxy resin has been proposed (for example, Patent Document 1). However, in Patent Document 1, when the acid value of the acid-modified polystyrene elastomer resin is low, the compatibility with other components is lowered, and the adhesive strength is not exhibited. In addition, regarding an adhesive for fixing a semiconductor wafer to a support at the time of polishing, an adhesive composition containing an acid-modified polystyrene elastomer resin has been proposed (for example, Patent Document 2).

In addition, thermoplastic polyimide derived from diamine compounds derived from aliphatic diamines such as dimer acids (dimer fatty acids) as raw materials, and amine compounds having at least two primary amine groups as functional groups have been proposed The crosslinked polyimide resin obtained by the reaction is applied to the adhesive layer of the coverlay film (for example, Patent Document 3). In the Example of patent document 3, it is also disclosed that the scaly talc is mix|blended with the thermoplastic polyimide composition which uses aliphatic diamine as a raw material. Here, the dimer acid is, for example, oleic acid, linoleic acid, linolenic acid, erucic acid, etc. which are obtained by using natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, and rapeseed oil fatty acid as raw materials, and purifying them. A dimerized fatty acid obtained by performing a Diels-Alder reaction, and it is known that a polybasic acid compound derived from a dimer acid can be used as a raw material for fatty acids or trimerized or more fatty acids. It can be obtained in the form of a composition (for example, Patent Document 4). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6705456 [Patent Document 2] International Publication No. WO2013/153904 [Patent Document 3] Japanese Patent No. 5777944 [Patent Document 4] Japanese Patent Laid-Open No. 2017-137375

[Problems to be Solved by Invention] Thermoplastic polyimides made from aliphatic diamines are soluble in solvents, excellent in adhesiveness, and good in handleability, so they are resin materials that can be effectively used as adhesives. , in addition to satisfying the above-mentioned various characteristics, it is also required to further reduce the dielectric loss tangent.

Therefore, an object of the present invention is to provide a polyimide composition which can form a resin film having both low dielectric loss tangent and excellent adhesiveness using thermoplastic polyimide.

[Technical means to solve the problem] The polyimide composition of the present invention contains the following (A) components and (B) components; (A) thermoplastic polyimide, and (B) a polystyrene elastomer resin having an acid value of 10 mgKOH/g or less, And content of the said (B) component is in the range of 10 weight part or more and 100 weight part or less with respect to 100 weight part of said (A) component.

In the polyimide composition of the present invention, the content ratio of the styrene unit in the component (B) may be within a range of 10% by weight or more and 65% by weight or less.

In the polyimide composition of the present invention, the thermoplastic polyimide may be obtained by reacting a tetracarboxylic anhydride component with a diamine component, and may contain 40 mol% or more of the diamine component relative to the diamine component. of aliphatic diamines.

The polyimide composition of the present invention can be as follows: the aliphatic diamine is a dimer diamine in which the two terminal carboxylic acid groups of the dimer acid are replaced by primary amino methyl groups or amine groups. The main component of the dimer diamine composition.

The polyimide composition of the present invention may further contain an amine-based compound having at least two primary amine groups as functional groups.

The resin film of the present invention is a resin film containing a thermoplastic resin layer, characterized in that: The thermoplastic resin layer contains the following (A) components and (B) components; (A) thermoplastic polyimide, and (B) a polystyrene elastomer resin having an acid value of 10 mgKOH/g or less,

In the resin film of the present invention, the temperature of the thermoplastic resin layer may be 10 measured by split post dielectric resonators (SPDR) after the thermoplastic resin layer is humidified under the constant temperature and humidity conditions of 23° C. and 50% RH for 24 hours. The dielectric loss tangent (Tanδ) at GHz is 0.0020 or less.

The laminate of the present invention is a laminate having a base material and an adhesive layer laminated on at least one surface of the base material, wherein the adhesive layer includes the resin film.

The coverlay film of the present invention is a coverlay film having a film material layer for coverlay and an adhesive layer laminated on the film material layer for coverlay, wherein the adhesive layer includes the resin film.

The resin-coated copper foil of the present invention is a resin-coated copper foil obtained by laminating an adhesive layer and a copper foil, wherein the adhesive layer includes the resin film.

The metal-clad laminate of the present invention is a metal-clad laminate having an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, wherein at least one of the insulating resin layers includes the resin film.

The circuit board of the present invention is obtained by performing wiring processing on the metal layer of the metal-clad laminate.

[Effect of invention] Since the polyimide composition of the present invention contains thermoplastic polyimide and a polystyrene elastomer resin having a specific acid value, it can be formed to have a practically sufficient peel strength while maintaining a low dielectric loss tangent resin film with excellent adhesion. Therefore, the polyimide composition and resin film of the present invention can be particularly preferably used as circuit board materials such as FPC in electronic equipment requiring high-speed signal transmission, for example. In addition, by improving the dielectric properties of the resin film, it can be applied to a receiver of a direct conversion method. Furthermore, since the peeling strength of a resin film can be improved, it can be applied to electronic equipment of all structures as a highly reliable low-dielectric adhesive.

Hereinafter, embodiments of the present invention will be described.

[Polyimide composition] The polyimide composition of one embodiment of the present invention contains the following (A) components and (B) components; (A) thermoplastic polyimide, and (B) A polystyrene elastomer resin having an acid value of 10 mgKOH/g or less.

<(A) component: thermoplastic polyimide> The thermoplastic polyimide as the (A) component is a solvent-soluble thermoplastic polyimide, and is obtained by reacting a tetracarboxylic anhydride component and a diamine component. Precursor polyamic acid is imidized. In addition, the term "thermoplastic polyimide" generally refers to a polyimide that is softened by heating and solidified by cooling, and the above process can be repeated and the glass transition temperature (Tg) can be clearly confirmed, but in the present invention, It means a polyimide whose glass transition temperature can be clearly confirmed in a temperature range of less than 150°C. In addition, from the viewpoint of thermocompression bonding properties at low temperatures, polyimide having a clear glass transition temperature in a temperature range of less than 100° C. is preferable, and it is more preferable to use a dynamic viscoelasticity measuring device (dynamic mechanical Polyamides having a storage elastic coefficient of 1.0×10 ⁸ Pa or more at 30°C and a storage elastic coefficient of less than 3.0×10 ⁷ Pa at glass transition temperature +30°C as measured by a dynamic mechanical analyzer (DMA)) amine. In addition, the term "non-thermoplastic polyimide" generally refers to a polyimide that does not show softening and adhesiveness even when heated, but in the present invention, it refers to measurement using a dynamic viscoelasticity measuring device (DMA). It is a polyimide having a storage elastic modulus at 30°C of 1.0×10 ⁹ Pa or more and a storage elastic modulus at 300°C of 3.0×10 ⁸ Pa or more.

(Tetracarboxylic anhydride component) The thermoplastic polyimide as the component (A) may contain a tetracarboxylic acid residue derived from a tetracarboxylic anhydride generally used for thermoplastic polyimide without particular limitation, but it is preferable to contain all the tetracarboxylic acid residues. A total of 90 mol% or more of tetracarboxylic acid residues derived from tetracarboxylic anhydrides represented by the following general formula (1) are contained. By containing 90 mol% or more of tetracarboxylic acid residues derived from the tetracarboxylic anhydride represented by the following general formula (1) in total with respect to all the tetracarboxylic acid residues, the flexibility and flexibility of the polyimide can be easily achieved. It is preferable to balance heat resistance. When the total of the tetracarboxylic acid residues derived from the tetracarboxylic anhydride represented by the following general formula (1) is less than 90 mol %, the solvent solubility of the polyimide tends to decrease.

[hua 1]

In the general formula (1), X represents a single bond or a divalent group selected from the following formulae.

[hua 2]

In the above formula, Z represents -C ₆ H ₄ -, -(CH ₂ )n- or -CH ₂ -CH(-OC(=O)-CH ₃ )-CH ₂ -, and n represents 1 to 20 Integer.

Examples of the tetracarboxylic anhydride represented by the general formula (1) include 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'- Benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyltetracarboxylic dianhydride (DSDA), 4,4'-oxydiphthalic anhydride ( ODPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propanedi Anhydride (BPADA), p-phenylene bis (trimellitic acid monoester anhydride) (TAHQ), ethylene glycol bis trimellitic anhydride (TMEG), etc. Among these, when 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) is used in particular, the adhesiveness of polyimide can be improved, and in addition, there are molecules present in the molecular skeleton. When a ketone group reacts with an amine group of an amine group compound used for crosslinking to be described later to form a C=N bond, the effect of improving heat resistance is likely to be exhibited. From this point of view, it is preferable to contain tetravalent tetracarboxylic acid residues (BTDA residues) derived from BTDA in an amount of preferably 50 mol% or more, more preferably 60 mol% or more with respect to all tetracarboxylic acid residues. ).

The thermoplastic polyimide as the component (A) may contain a tetracarboxylic acid residue derived from an acid anhydride other than the tetracarboxylic acid anhydride represented by the general formula (1) within a range that does not impair the effects of the invention. It does not specifically limit as such a tetracarboxylic acid residue, For example, pyromellitic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3, 3'-benzophenone tetracarboxylic dianhydride or 2,3,3',4'-benzophenone tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic acid Dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 3,3'',4,4''-p-triphenyltetracarboxylic dianhydride, 2,3,3'',4'' -p-triphenyltetracarboxylic dianhydride or 2,2'',3,3''-p-triphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride Or 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride or bis(3,4-dicarboxyphenyl)methane dianhydride , bis(2,3-dicarboxyphenyl) bis(2,3-dicarboxyphenyl) bis(3,4-dicarboxyphenyl) bis(3,4-dicarboxyphenyl) bis(3,4-dicarboxyphenyl) bis(2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride Or 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-phenanthrene-tetracarboxylic dianhydride, 1,2,6,7-phenanthrene-tetracarboxylic acid Dianhydride or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,3,6,7-anthracene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrakis Fluoropropane dianhydride, 2,3,5,6-cyclohexane dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2 ,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid di anhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3, 6,7-(or 1,4,5,8-)tetrachloronaphthalene-1,4,5,8-(or 2,3,6,7-)tetracarboxylic dianhydride, 2,3,8, 9-perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride or 5,6,11,12- Perylene-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3, 4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, etc. Tetracarboxylic acid residues derived from aromatic tetracarboxylic dianhydrides.

(diamine component) The thermoplastic polyimide as the component (A) is preferably a diamine component containing an aliphatic diamine in an amount of preferably 40 mol % or more, more preferably 60 mol % or more with respect to all the diamine components as a raw material. That is, the thermoplastic polyimide as the component (A) preferably contains diamine derived from aliphatic diamine in an amount of preferably 40 mol % or more, more preferably 60 mol % or more with respect to all the diamine residues Residues. By containing the diamine residue derived from the aliphatic diamine in the above amount, the dielectric properties of the polyimide can be improved, and it can be brought about by lowering the glass transition temperature (lowering Tg) of the polyimide. The improvement of thermocompression bonding properties and the reduction of the elastic modulus to relieve internal stress. When the diamine residue derived from aliphatic diamine is less than 40 mol % with respect to all the diamine residues, the effect of improving the dielectric loss tangent and thermocompression bonding properties may not be sufficiently obtained. Here, as the aliphatic diamine, for example, a dimer diamine in which the two terminal carboxylic acid groups of the dimer acid are substituted with a primary amino methyl group or an amine group can be used as a main component. Amine composition, hexamethylenediamine, dodecanediamine, cyclohexanediamine, polyoxyalkyleneamine, 4,4-diaminodicyclohexylmethane, etc., particularly preferably dimer dimer Amine composition.

(dimer diamine composition) The dimer diamine composition contains the following component (a) as a main component, and the amounts of the component (b) and the component (c) are controlled.

(a) Dimer Diamine The so-called dimer diamine as the component (a) means that the two terminal carboxylic acid groups (-COOH) of the dimer acid are substituted with primary aminomethyl groups (-CH ₂ -NH ₂ ) or the diamine of amine group (-NH ₂ ). Dimer acid is a known dibasic acid obtained by intermolecular polymerization of unsaturated fatty acids. Its industrial manufacturing process has been roughly standardized in the industry, and unsaturated fatty acids with carbon numbers of 11 to 22 are added to Dimerized. Industrially obtained dimer acids are mainly composed of dibasic acids having 36 carbon atoms obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid, linoleic acid, and linolenic acid, depending on the degree of purification On the other hand, it contains arbitrary amounts of monomeric acid (18 carbon atoms), trimer acid (54 carbon atoms), and other polymerized fatty acids having 20 to 54 carbon atoms. In addition, the double bond remains after the dimerization reaction, but in the present invention, it is assumed that the dimer acid also includes an acid which further undergoes a hydrogenation reaction to reduce the degree of unsaturation. The dimer diamine as the component (a) can be defined as a primary aminomethyl group in which the terminal carboxylic acid group of a dibasic acid compound having a carbon number in the range of 18 to 54, preferably in the range of 22 to 44, is substituted with a primary aminomethyl group. diamine compound derived from a base or an amine group.

As a feature of the dimer diamine, properties derived from the dimer acid skeleton can be imparted. That is, the dimer diamine is an aliphatic macromolecule with a molecular weight of about 560 to 620, and thus can increase the molar volume of the molecule and relatively reduce the polar group of the polyimide. It is considered that the characteristics of such a dimer acid type diamine contribute to the improvement of the dielectric properties by reducing the relative permittivity and the dielectric loss tangent while suppressing the decrease in the heat resistance of the polyimide. In addition, since it has two freely movable hydrophobic chains having 7 to 9 carbon atoms and two chain-like aliphatic amine groups having a length close to 18 carbon atoms, it is possible not only to impart flexibility to polyimide, but also to impart flexibility to the polyimide. Since the polyimide has an asymmetric chemical structure or a non-planar chemical structure, it is considered that the lowering of the dielectric constant and the lowering of the dielectric loss tangent of the polyimide can be achieved.

In the dimer diamine composition, the content of the dimer diamine as the component (a) is preferably increased to 96 wt % or more, preferably 97 wt % or more, more preferably 98 wt % or more by a purification method such as molecular distillation. Compositions. By setting the content of the dimer diamine as the component (a) to 96% by weight or more, the spread of the molecular weight distribution of the polyimide can be suppressed. In addition, if technically feasible, it is preferable that the whole (100% by weight) of the dimer diamine composition includes the dimer diamine as the component (a).

(b) a monoamine compound obtained by substituting a terminal carboxylic acid group of a monobasic acid compound having a carbon number of 10 to 40 with a primary aminomethyl group or an amine group; The monobasic acid compound in the range of carbon number 10 to 40 is the monobasic unsaturated fatty acid in the range of carbon number 10 to 20 derived from the raw material of dimer acid, and the by-product in the production of dimer acid. A mixture of monobasic acid compounds having a carbon number in the range of 21 to 40. The monoamine compound is a compound obtained by substituting the terminal carboxylic acid group of the monobasic acid compound with a primary aminomethyl group or an amine group.

The monoamine compound which is a component (b) is a component which suppresses the molecular weight increase of polyimide. During the polymerization of polyamic acid or polyimide, the monofunctional amine group of the monoamine compound reacts with the terminal acid anhydride group of polyamic acid or polyimide, whereby the terminal acid anhydride group is sealed, Thereby, the molecular weight increase of polyamic acid or polyimide is suppressed.

(c) An amine compound obtained by substituting a terminal carboxylic acid group of a polybasic acid compound having a hydrocarbon group having a carbon number in the range of 41 to 80 with a primary aminomethyl group or an amino group (wherein the dimer diamine except); The polybasic acid compound having a hydrocarbon group having a carbon number in the range of 41 to 80 is a polybasic acid compound mainly composed of a tribasic acid compound having a carbon number in the range of 41 to 80, which is a by-product when producing a dimer acid. In addition, a polymerized fatty acid other than the dimer acid having 41 to 80 carbon atoms may be contained. The amine compound is a compound obtained by substituting the terminal carboxylic acid group of the polybasic acid compound with a primary aminomethyl group or an amine group.

The amine compound as the component (c) is a component that promotes an increase in the molecular weight of the polyimide. The molecular weight of polyimide is rapidly increased by reacting a trifunctional or higher amine group mainly composed of a triamine body derived from a trimer acid with a terminal acid anhydride group of polyimide or polyimide. In addition, amine compounds derived from polymerized fatty acids other than dimer acids having 41 to 80 carbon atoms also increase the molecular weight of polyimide and cause gelation of polyimide or polyimide.

When quantifying each component of the dimer diamine composition by measurement using gel permeation chromatography (GPC), in order to easily confirm the quantification of each component of the dimer diamine composition. For peak start, peak top, and peak end, the dimer diamine composition was treated with acetic anhydride and pyridine, and cyclohexanone was used as an internal standard. . Each component was quantified using the area percentage of the GPC chromatogram using the sample prepared in the manner described. The peak start point and peak end point of each component can be regarded as the minimum value of each peak curve, and the area percentage of the chromatogram can be calculated based on the minimum value of each peak curve.

In addition, in the dimer diamine composition used in the present invention, the total of the component (b) and the component (c) is preferably 4% or less in terms of the area percentage of the chromatogram measured by GPC, preferably 4% or less. less than 4%. By making the total of the component (b) and the component (c) 4% or less, the expansion of the molecular weight distribution of the polyimide can be suppressed.

In addition, the area percentage of the chromatogram of the component (b) is preferably 3% or less, more preferably 2% or less, and still more preferably 1% or less. By setting it as such a range, the fall of the molecular weight of a polyimide can be suppressed, and the range of the molar ratio of the input of a tetracarboxylic anhydride component and a diamine component can be expanded. Moreover, (b) component may not be contained in a dimer diamine composition.

In addition, the area percentage of the chromatogram of the component (c) is preferably 2% or less, preferably 1.8% or less, and more preferably 1.5% or less. By setting it as such a range, the molecular weight of a polyimide can be suppressed from increasing rapidly, and the dielectric loss tangent of a resin film can be suppressed from rising at a frequency in a wide range. Moreover, (c) component may not be contained in the dimer diamine composition.

In addition, when the ratio (b/c) of the area percentages of the chromatograms of the component (b) and the component (c) is 1 or more, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic anhydride component/ Diamine component) is preferably 0.97 or more and less than 1.0, and the molecular weight of the polyimide can be more easily controlled by using such a molar ratio.

In addition, when the ratio (b/c) of the area percentages of the chromatograms of the component (b) and the component (c) is less than 1, the molar ratio of the tetracarboxylic anhydride component and the diamine component (tetracarboxylic anhydride component/diamine component) is preferably 0.97 or more and 1.1 or less, and the molecular weight of the polyimide can be more easily controlled by using such a molar ratio.

The weight average molecular weight of the polyimide is preferably in the range of, for example, 10,000 to 200,000. In addition, when used as an adhesive for FPC, for example, the weight average molecular weight of the polyimide is more preferably in the range of 20,000 to 150,000, and more preferably in the range of 40,000 to 150,000. When the weight-average molecular weight of the polyimide is less than 20,000, the flow resistance tends to deteriorate. On the other hand, when the weight average molecular weight of the polyimide exceeds 150,000, the viscosity increases excessively and becomes insoluble in the solvent, and defects such as uneven thickness of the adhesive layer and streaks tend to occur during the coating operation.

The dimer diamine composition is preferably purified for the purpose of reducing components other than the dimer diamine as the component (a). Although it does not specifically limit as a purification method, Well-known methods, such as distillation method and precipitation purification, are preferable. The dimer diamine composition before purification can be obtained as a commercial item, for example, PRIAMINE 1073 (trade name) manufactured by Croda Japan, Inc., Croda Japan PRIAMINE 1074 (trade name) manufactured by the company, PRIAMINE 1075 (trade name) manufactured by Croda Japan, etc.

As a diamine compound other than aliphatic diamine used for polyimide, an aromatic diamine compound is mentioned. Specific examples of these include 1,4-diaminobenzene (p-PDA; p-phenylenediamine), 2,2'-dimethyl-4,4'-diaminobiphenyl (m- TB), 2,2'-n-propyl-4,4'-diaminobiphenyl (m-NPB), 4-aminophenyl-4'-aminobenzoate (APAB), 2, 2-Bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]zine, bis[4-(3-aminophenoxy) base)] biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)] Phenoxy)phenyl] ether, bis[4-(3-aminophenoxy)]benzophenone, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 3,3'-Dimethyl-4,4'-diaminobiphenyl, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-2,6-dimethyl Aniline, 4,4'-methylene-2,6-diethylaniline, 3,3'-diaminodiphenylethane, 3,3'-diaminobiphenyl, 3,3'- Dimethoxybenzidine, 3,3''-diamino-p-terphenyl, 4,4'-[1,4-phenylene bis(1-methylethylene)]dianiline, 4, 4'-[1,3-phenylene bis(1-methylethylene)]dianiline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-tert-butylphenyl) ) ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5 -Aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-tert-butyl)toluene, 2,4-diamine toluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5- Diaminopyridine, 2,5-diamino-1,3,4-oxadiazole, piperazine, 2'-methoxy-4,4'-diaminobenzylaniline, 4,4' -Diaminobenzylaniline, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 6-amino-2-(4-aminophenoxy)benzene Diamine compounds such as oxazole and 1,3-bis(3-aminophenoxy)benzene.

Polyimide can be produced by reacting the tetracarboxylic anhydride component and the diamine component in a solvent to generate polyimide and then heating and ring-closing. For example, by dissolving the tetracarboxylic anhydride component and the diamine component in an organic solvent at approximately equimolar levels, and stirring at a temperature in the range of 0° C. to 100° C. for 30 minutes to 24 hours to carry out a polymerization reaction, a polymer as a polymer can be obtained. Polyamides that are precursors of imines. During the reaction, the reaction components are dissolved in the organic solvent so that the produced precursor is in the range of 5 to 50 wt %, preferably in the range of 10 to 40 wt %. As the organic solvent used in the polymerization reaction, for example, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide can be mentioned. Amine, N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethylsulfoxide (DMSO), hexamethylphosphamide, N-methylcaprolactamide, dimethyl sulfate, cycloheximide Hexanone, methylcyclohexane, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), methanol, ethanol, benzyl alcohol, cresol, etc. These solvents may be used in combination of two or more, and aromatic hydrocarbons such as xylene and toluene may also be used in combination. In addition, the usage-amount of such an organic solvent is not specifically limited, It is preferable to adjust the usage-amount so that the density|concentration of the polyamic acid solution obtained by a polymerization reaction becomes about 5 weight% - 50weight%.

The synthesized polyamic acid is usually advantageously used as a reaction solvent solution, and can be concentrated, diluted or replaced with other organic solvents as necessary. In addition, polyamic acid is generally used advantageously because it is excellent in solvent solubility. The viscosity of the polyamic acid solution is preferably in the range of 500 cps to 100,000 cps. If it deviates from this range, it is easy to generate|occur|produce defects, such as thickness unevenness and a streak, in a film|membrane at the time of application|coating operation by a coater etc..

The method for imidizing polyimide to form polyimide is not particularly limited, for example, it can be preferably used in the solvent at a temperature in the range of 80°C to 400°C for 1 hour to Heat treatment such as heating is performed for 24 hours. In addition, regarding the temperature, heating may be performed under a fixed temperature condition, or the temperature may be changed in the middle of the step.

In the thermoplastic polyimide as the component (A), the molar ratio of each of the above-mentioned tetracarboxylic anhydride component and diamine component is selected, or when two or more tetracarboxylic anhydride components or diamine components are used. , can control dielectric properties, thermal expansion coefficient, tensile elastic coefficient, glass transition temperature, etc. In addition, when the thermoplastic polyimide as the component (A) has a plurality of structural units of the polyimide, it may be present in the form of a block or may be present randomly, and it is preferably present randomly exist.

The thermoplastic polyimide as the component (A) preferably has an imide group concentration of 22% by weight or less, more preferably 20% by weight or less. Here, the "imide group concentration" refers to a value obtained by dividing the molecular weight of the imide group (-(CO) ₂ -N-) in the polyimide by the molecular weight of the entire structure of the polyimide. When the imide group concentration exceeds 22 wt %, the molecular weight of the resin itself becomes small, and the low hygroscopicity also deteriorates due to the increase in polar groups, and the Tg and the tensile modulus increase.

The thermoplastic polyimide as the component (A) preferably has a completely imidized structure. Among them, a part of polyimide may be amide acid. Its imidization rate can be determined by using a Fourier transform infrared spectrophotometer (commercial product: manufactured by Nippon Shoko Co., Ltd., trade name: FT/IR620), and by the attenuated total reflection (ATR) method. The infrared absorption spectrum of the imide film was measured and calculated from the absorbance at 1780 cm ^-1 derived from the C=O expansion of the imide group using the benzene ring absorber around 1015 cm ^-1 as a reference.

<(B) component: polystyrene elastomer resin> The polystyrene elastomer resin as the component (B) is a copolymer of styrene or a derivative thereof and a conjugated diene compound, and includes a hydrogenated product thereof. Here, although it does not specifically limit as styrene or its derivative(s), Styrene, methylstyrene, butylstyrene, divinylbenzene, vinyltoluene, etc. are illustrated. Moreover, it does not specifically limit as a conjugated diene compound, Butadiene, isoprene, 1, 3- pentadiene, etc. are illustrated. In addition, the polystyrene elastomer resin is preferably hydrogenated. By hydrogenation, thermal stability is further improved, deterioration such as decomposition or polymerization is less likely to occur, aliphatic properties are improved, and compatibility with the thermoplastic polyimide as the component (A) is improved.

The copolymer structure of the polystyrene elastomer resin as the component (B) may be a block structure or a random structure. Preferred specific examples of the polystyrene elastomer resin include styrene-butadiene-styrene block copolymer (styrene-butadiene-styrene, SBS), styrene-butadiene-butene-styrene Block copolymer (styrene-butadiene-butylene-styrene, SBBS), styrene-ethylene-butylene-styrene block copolymer (styrene-ethylene-butylene-styrene, SEBS), styrene-ethylene-propylene-benzene Ethylene block copolymer (styrene-ethylene-propylene-styrene, SEPS), styrene-ethylene-ethylene/propylene-styrene block copolymer (styrene-ethylene-ethylene/propylene-styrene, SEEPS), etc., but not It is limited to these specific examples.

The acid value of the polystyrene elastomer resin as the component (B) is 10 mgKOH/g or less, preferably 1 mgKOH/g or less, and more preferably 0 mgKOH/g. By blending a polystyrene elastomer resin with an acid value of 10 mgKOH/g or less in the polyimide composition, the dielectric loss tangent at the time of forming the resin film can be reduced, and good peel strength can be maintained. On the other hand, when the acid value exceeds 10 mgKOH/g, the dielectric properties are deteriorated due to the increase in polar groups, the compatibility with the component (A) is deteriorated, and the adhesiveness at the time of forming the resin film is lowered. Therefore, the lower the acid value, the better, and the resin without acid modification (that is, the resin having an acid value of 0 mgKOH/g) is most suitable as the component (B) of the present invention. In the present invention, when the thermoplastic polyimide as the component (A) contains a residue derived from an aliphatic diamine, excellent adhesiveness can be exhibited, so even if it is used without acid modification (ie, A polystyrene elastomer resin with strong aliphatic properties can also avoid the decrease in adhesive strength which is a concern in Patent Document 1.

The polystyrene elastomer resin as the component (B) preferably has a content ratio of styrene units [-CH ₂ CH(C ₆ H ₅ )-] within a range of 10% by weight or more and 65% by weight or less, more preferably It is in the range of 20 weight% or more and 65 weight% or less, Preferably it exists in the range of 30 weight% or more and 60 weight% or less. When the content ratio of the styrene unit in the polystyrene elastomer resin is less than 10 wt %, the elastic modulus of the resin decreases and the handleability as a film deteriorates, and when it becomes high and exceeds 65 wt %, the resin becomes rigid and it is difficult to In addition to using it as an adhesive, the rubber component in the polystyrene elastomer resin decreases, which leads to deterioration of dielectric properties. In addition, when the content ratio of the styrene unit is within the above-mentioned range, the ratio of the aromatic ring in the resin film becomes high. Therefore, in the process of manufacturing a circuit board using the resin film, through holes (through holes) and In the case of blind holes, the absorbency in the ultraviolet region can be improved, and the laser processability can be further improved.

The weight average molecular weight of the polystyrene elastomer resin as the component (B) is, for example, preferably within a range of 50,000 to 300,000, and more preferably within a range of 80,000 to 270,000. When the weight-average molecular weight of the component (B) is less than the above-mentioned range, the effect of improving the dielectric properties may be reduced. Conversely, when the weight-average molecular weight of the component exceeds the above-mentioned range, the viscosity of the polyimide composition will be reduced. When it becomes high, it may become difficult to manufacture a resin film.

As the polystyrene elastomer resin as the component (B), as long as the acid value is 10 mgKOH/g or less, a commercially available product can be appropriately selected and used. As such commercially available polystyrene elastomer resins, for example, A1535HU (trade name), G1652MU (trade name), G1726VS (trade name), and G1645VS (trade name) manufactured by KRATON can be preferably used , FG1901GT (trade name), G1650MU (trade name), G1654HU (trade name), G1730VO (trade name), MD1653MO (trade name), etc.

[Allocation amount] The content of the (B) component in the polyimide composition is in the range of 10 parts by weight or more and 100 parts by weight or less, preferably in the range of 20 parts by weight or more and 90 parts by weight or less with respect to 100 parts by weight of the (A) component. It is more preferable to be within the range of 30 parts by weight or more and 80 parts by weight or less. If the content of the (B) component with respect to 100 parts by weight of the (A) component is less than 10 parts by weight, the effect of reducing the dielectric loss tangent may not be sufficiently exhibited. On the other hand, when the weight ratio of the (B) component exceeds 100 parts by weight, the adhesiveness at the time of forming the resin film decreases, the solid content concentration in the polyimide composition becomes too high, the viscosity increases, and the workability is improved. reduced situation.

[optional ingredient] When the thermoplastic polyimide as the component (A) has a ketone group, the ketone group and the amine group compound having at least two primary amine groups as functional groups (in this specification may be referred to as The amine group of the "amine group compound for crosslinking") reacts to form a C=N bond, which can form a crosslinking structure. By forming a crosslinked structure, the heat resistance of the thermoplastic polyimide forming the adhesive layer can be improved. Therefore, the polyimide composition of the present embodiment may contain the crosslink-forming amino compound as an optional component.

As a preferable tetracarboxylic anhydride in order to form a polyimide having a ketone group, for example, 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA) is mentioned, and as a diamine compound, For example, 4,4'-bis(3-aminophenoxy)benzophenone (BABP), 1,3-bis[4-(3-aminophenoxy)benzyl]benzene ( BABB) and other aromatic diamines. For the purpose of forming a cross-linked structure, the polyimide composition of the present embodiment preferably contains a thermoplastic polyimide as the component (A) and an amine compound for forming a cross-link, the thermoplastic polyimide being the component (A). The imide contains preferably 50 mol% or more, more preferably 60 mol% or more of BTDA residues derived from BTDA with respect to all tetracarboxylic acid residues.

As an amine compound for crosslinking formation, (I) a dihydrazide compound, (II) aromatic diamine, (III) aliphatic amine, etc. are illustrated. Among them, a dihydrazide compound is preferable. Aliphatic amines other than the dihydrazide compound easily form a cross-linked structure even at room temperature, and there are concerns about the storage stability of the varnish. On the other hand, aromatic diamines require high temperature in order to form a cross-linked structure. In this way, when a dihydrazide compound is used, both the storage stability of the varnish and the shortening of the curing time can be achieved. As the dihydrazine compound, for example, dihydrazine oxalate, dihydrazine malonate, dihydrazine succinate, dihydrazine glutarate, dihydrazine adipic acid, and dihydrazine pimelic acid are preferred. , Dihydrazine suberic acid, dihydrazine azelaic acid, dihydrazine sebacate, dihydrazine dodecanedioic acid, dihydrazine maleate, dihydrazine fumarate, diglycolic acid dihydrazine hydrazine, dihydrazine tartrate, dihydrazine malate, dihydrazine phthalate, dihydrazine isophthalate, dihydrazine terephthalate, 2,6-naphthoic acid dihydrazine, 4, Dihydrazide compounds such as 4-bisphenyl dihydrazine, 1,4-naphthoic acid dihydrazine, 2,6-pyridine diacid dihydrazide, and itaconic acid dihydrazine. The above dihydrazide compounds may be used alone or in combination of two or more.

In addition, the amine-based compounds such as (I) dihydrazide compound, (II) aromatic diamine, (III) aliphatic amine may be, for example, a combination of (I) and (II), (I) and (III) ) and the combination of (I) and (II) and (III), the supercategory is used in combination of two or more.

In addition, from the viewpoint of making the network structure formed by the crosslinking by the crosslinking amine compound denser, the molecular weight of the crosslinking amine compound used in the present invention (in the When the base compound is an oligomer, the weight average molecular weight is preferably 5,000 or less, more preferably 90 to 2,000, and still more preferably 100 to 1,500. Among them, an amino compound for forming a crosslink having a molecular weight of 100 to 1,000 is particularly preferable. If the molecular weight of the amine compound for crosslinking is less than 90, one amine group of the amine compound for crosslinking is limited to form a C=N bond with the ketone group of the polyimide resin, and the remaining amine groups have a three-dimensional volume around the periphery. becomes larger, so the remaining amine groups tend to be less likely to form a C=N bond.

When the ketone group in the thermoplastic polyimide as the component (A) and the amine compound for crosslinking are formed by crosslinking, the above-mentioned crosslinking is added to the resin solution containing the component (A). The amine-based compound, the ketone group in the thermoplastic polyimide is subjected to condensation reaction with the primary amine group of the amine-based compound for crosslinking. By the condensation reaction, the resin solution hardens and becomes a hardened product. In this case, the addition amount of the amino compound for crosslinking can be 0.004 mol to 1.5 mol in total, preferably 0.005 mol to 1.2 mol per 1 mol of the ketone group, the primary amine group. ear, more preferably 0.03 mol to 0.9 mol, most preferably 0.04 mol to 0.6 mol. Regarding the addition amount of the amino compound for crosslinking in which the total amount of primary amino groups is less than 0.004 mol relative to 1 mole of keto group, the crosslinking by the amino compound for forming crosslinking is insufficient, so it is difficult to express There is a tendency for heat resistance after curing, and if the addition amount of the crosslink-forming amine compound exceeds 1.5 mol, the unreacted cross-linking-forming amine compound acts as a thermoplastic, and there is a possibility of causing the adhesive layer to act as an adhesive. Tendency to reduce heat resistance.

The conditions for the condensation reaction for crosslink formation are that the ketone group in the thermoplastic polyimide as the component (A) reacts with the primary amine group of the amine compound for crosslink formation to form an imine bond (C =N key), there are no special restrictions. The temperature of the thermal condensation is for simplification of the condensation step when a thermal condensation reaction is performed after the synthesis of the thermoplastic polyimide as the component (A) when the water generated by the condensation is released to the outside of the system, or the like. For this reason, it is preferable to exist in the range of 120 degreeC - 220 degreeC, for example, and it is more preferable to exist in the range of 140 degreeC - 200 degreeC. The reaction time is preferably about 30 minutes to 24 hours. The end point of the reaction can be measured, for example, by measuring an infrared absorption spectrum using a Fourier transform infrared spectrophotometer (commercial product: FT/IR620 manufactured by JASCO Corporation), and using a polyimide resin derived from a polyimide resin in the vicinity of 1670 cm ⁻¹ . It was confirmed that the absorption peak of the ketone group decreased or disappeared, and the absorption peak derived from the imine group appeared in the vicinity of 1635 cm ⁻¹ .

The heating condensation of the ketone group of the thermoplastic polyimide as the component (A) and the primary amine group of the amine compound for crosslinking can be performed, for example, by the following method: (1) A method of adding an amine compound for crosslinking and heating immediately after the synthesis (imidation) of the thermoplastic polyimide as the component (A); (2) Preliminarily throwing an excessive amount of an amine-based compound as a diamine component, and immediately following the synthesis (imidation) of thermoplastic polyimide as the component (A), those that do not participate in imidization or imidization A method in which the remaining amine-based compound is utilized as a crosslink-forming amine-based compound and heated with thermoplastic polyimide; or (3) A method of heating the polyimide composition to which the amino compound for forming crosslinking is added after being processed into a predetermined shape (for example, after coating on an arbitrary substrate or after forming into a film shape).

The case where an imine bond is formed in the formation of the crosslinked structure in order to impart heat resistance to the thermoplastic polyimide as the component (A) has been described, but the present invention is not limited to this. The curing method of polyimide, for example, epoxy resin, epoxy resin curing agent, maleimide, activated ester resin, resin with styrene skeleton and other compounds having unsaturated bonds can be prepared for curing. .

In the polyimide composition of the present embodiment, inorganic fillers, organic fillers, plasticizers, hardening accelerators, coupling agents, pigments, flame retardants, etc. can be appropriately blended as necessary within a range that does not impair the effects of the invention. as an optional ingredient. Here, examples of inorganic fillers include silica, alumina, beryllium oxide, niobium oxide, titanium oxide, magnesium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, Magnesium fluoride, silicon gallium fluoride, metal phosphinate, etc. These can be used alone or in a mixture of two or more. Moreover, as an arbitrary component, other resin components, such as an epoxy resin, a fluororesin, and an olefin resin, can also be mix|blended, for example.

Furthermore, the polyimide composition of the present embodiment may contain a solvent such as an organic solvent. Since the thermoplastic polyimide as the component (A) has solvent solubility, and the polystyrene elastomer resin as the component (B) also shows good solubility in aromatic hydrocarbon-based solvents such as xylene and toluene, Therefore, the polyimide composition of the present embodiment can be prepared as a polyimide solution (varnish) containing a solvent. As the organic solvent, for example, it is preferable to use N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N,N-diethylacetamide , N-methyl-2-pyrrolidone (NMP), 2-butanone, dimethyl sulfoxide (DMSO), hexamethylphosphamide, N-methyl caprolactam, dimethyl sulfate, cyclohexyl One or two or more of ketone, dioxane, tetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, cresol, etc. are mixed with the aromatic hydrocarbon solvent in an arbitrary ratio mixed media. The content of the solvent is not particularly limited, but it is preferably used after adjusting the concentration of the polyamic acid or polyimide in an amount of about 5 to 30 wt %.

[viscosity] The viscosity of the polyimide composition is preferably in the range of, for example, 3,000 cps to 100,000 cps as a viscosity range for improving workability at the time of coating the polyimide composition and easily forming a coating film with a uniform thickness , more preferably within the range of 5000 cps to 50000 cps. If it deviates from the said viscosity range, it is easy to generate|occur|produce defects, such as thickness unevenness and a streak, in a film at the time of coating operation|work using a coater etc..

[Preparation of Polyimide Composition] The polyimide composition can be prepared, for example, by preparing and mixing a polystyrene elastomer resin in a thermoplastic polyimide resin solution prepared using an arbitrary solvent. At this time, in order to uniformly mix the thermoplastic polyimide and the polystyrene elastomer resin, the polystyrene elastomer resin may be mixed in a state where the polystyrene elastomer resin is dissolved in a solvent, or the polystyrene elastomer resin may be added The resin shows high solubility in solvents.

The polyimide composition of the present embodiment is a polyimide composition having excellent flexibility and thermoplasticity when an adhesive layer is formed using the polyimide composition. Therefore, for example, in FPC, a rigid/flexible circuit board, etc., it has preferable characteristics in applications, such as a material of an adhesive agent layer, and the adhesive agent for coverlay films which protect a wiring part.

[resin film] The resin film according to the present embodiment is a single-layer or multi-layer resin film including a thermoplastic resin layer whose main component is the solid content (the remainder after removing the solvent) of the polyimide composition. Membrane. That is, the thermoplastic resin layer contains (A) component and (B) component; (A) thermoplastic polyimide, and (B) a polystyrene elastomer resin having an acid value of 10 mgKOH/g or less, And content of the said (B) component is in the range of 10 weight part or more and 100 weight part or less with respect to 100 weight part of said (A) component. The resin film of the present embodiment has excellent high-frequency characteristics and excellent adhesiveness (particularly, peel strength).

The resin film of the present embodiment is not particularly limited as long as it is a film containing the insulating resin of the thermoplastic resin layer, and may be a film (sheet) containing only the insulating resin, or may be laminated on copper foil, glass plate, polystyrene A film of insulating resin in the state on a substrate such as a resin sheet such as an imide-based film, a polyamide-based film, and a polyester-based film.

(Relative permittivity) In order to ensure impedance matching when used in circuit boards such as FPC, for example, and to reduce electrical signal loss, the resin film of the present embodiment is conditioned at 10 GHz after 24 hours of humidification under constant temperature and humidity conditions of 23° C. and 50% RH. The relative permittivity (ε) of , is preferably 3.3 or less, more preferably 3.1 or less. When the relative permittivity exceeds 3.3, for example, when it is used for a circuit board such as an FPC, problems such as loss of electrical signals are likely to occur in the transmission path of high-frequency signals.

(dielectric loss tangent) In addition, in order to reduce the loss of electrical signals when the resin film of the present embodiment is used for circuit boards such as FPC, for example, the dielectric loss angle at 10 GHz after humidity is adjusted for 24 hours under the constant temperature and humidity conditions of 23° C. and 50% RH. The tangent (Tanδ) is preferably 0.0020 or less, more preferably 0.0018 or less. When the dielectric loss tangent exceeds 0.0020, for example, when it is used for a circuit board such as an FPC, problems such as loss of electrical signals are likely to occur in the transmission path of high-frequency signals.

(glass transition temperature) The glass transition temperature (Tg) of the resin film of the present embodiment is preferably 250° C. or lower, more preferably 40° C. or higher and 200° C. or lower. Since the Tg of the resin film is 250° C. or lower, thermocompression bonding can be performed at a low temperature, so that internal stress generated during lamination can be relieved, and dimensional changes after circuit processing can be suppressed. When the Tg of the resin film exceeds 250° C., the subsequent temperature becomes high, and there is a fear that the dimensional stability after circuit processing is impaired.

(thickness) The thickness of the resin film of the present embodiment is preferably within a range of, for example, 5 μm or more and 125 μm or less, and more preferably within a range of 8 μm or more and 100 μm or less. If the thickness of the resin film is less than 5 μm, there is a possibility that defects such as wrinkles may occur at the time of transportation such as production of the resin film. On the other hand, if the thickness of the resin film exceeds 125 μm, the productivity of the resin film will deteriorate. Reduced worry.

(tensile elastic coefficient) The tensile modulus of elasticity of the resin film of the present embodiment is preferably in the range of 0.1 GPa to 3.0 GPa, more preferably 0.2 GPa to 2.0 GPa, from the viewpoints of reducing the occurrence of wrinkles, preventing the inclusion of air bubbles during lamination, and handling properties. In the range.

(maximum elongation) The maximum elongation of the resin film of the present embodiment is preferably within the range of 30% to 200%, more preferably 60% to 160%, from the viewpoint of flexibility and crack prevention when used as an insulating resin layer of FPC. In the range.

Since the resin film of the present embodiment has a low dielectric loss tangent and excellent adhesiveness, it is effectively used as an adhesive in an adhesive layer in a coverlay film, a circuit board, a multilayer circuit board, a copper foil with resin, and the like layer, with substrate bonding sheet (bondply), pure glue bonding sheet (bonding sheet), etc.

[laminated body] The laminated body which concerns on one Embodiment of this invention has a base material, and the adhesive bond layer laminated|stacked on at least one surface of the said base material, and the adhesive bond layer contains the said resin film. In addition, the laminated body may include arbitrary layers other than those described above. As a base material in a laminated body, the base material of inorganic materials, such as copper foil and a glass plate, or the base material of resin materials, such as a polyimide-type film, a polyamide-type film, and a polyester-type film, is mentioned, for example. As a preferable form of a laminated body, a coverlay film, a copper foil with resin, etc. are mentioned.

[cover film] The coverlay film as one form of the laminate has a coverlay film material layer as a base material, and an adhesive layer laminated on one side of the coverlay film material layer, and the adhesive layer includes the resin film. In addition, the cover film may include any layers other than those described above.

The material of the film material layer for covering is not particularly limited, and for example, polyimide-based films such as polyimide resins, polyetherimide resins, and polyimide-imide resins, or polyimide-based films, polyester film, etc. Among them, it is preferable to use a polyimide-based film having excellent heat resistance. In addition, in order to effectively express light-shielding properties, concealment properties, design properties, etc., the coating film material may contain a black pigment, and may contain a matting pigment that suppresses surface gloss within a range that does not impair the effect of improving the dielectric properties. Arbitrary ingredients.

The thickness of the film material layer for covering is not particularly limited, but, for example, it is preferably within a range of 5 μm or more and 100 μm or less. In addition, the thickness of the adhesive layer is not particularly limited, but, for example, it is preferably within a range of 10 μm or more and 75 μm or less.

The coverlay film of this embodiment can be manufactured by the method illustrated below. First, as a first method, after applying a varnish-like polyimide composition containing a solvent to one side of the film material layer for covering, for example, drying at a temperature of 80° C. to 180° C. to form an adhesive layer, it is possible to form an adhesive layer. A coverlay film having a film material layer for coverlay and an adhesive layer is formed.

In addition, as a second method, a varnish-like polyimide composition containing a solvent is applied to an arbitrary substrate, and the resin for adhesive layer is formed by drying, for example, at a temperature of 80° C. to 180° C. and then peeling off. A cover film can be formed by thermocompression bonding of the resin film and the film material layer for cover at a temperature of, for example, 60°C to 220°C.

[Copper foil with resin] The copper foil with resin which is another form of a laminated body is obtained by laminating an adhesive layer on at least one side of a copper foil as a base material, and the adhesive layer includes the resin film. In addition, the copper foil with resin of the present embodiment may include any layers other than those described above.

The thickness of the adhesive layer in the copper foil with resin is preferably in the range of 2 μm to 125 μm, for example, and more preferably in the range of 2 μm to 100 μm. If the thickness of the adhesive layer is less than the lower limit value, problems such as insufficient adhesiveness cannot be ensured in some cases. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability may occur. In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent, it is preferable to set the thickness of the adhesive layer to be 3 μm or more.

The material of the copper foil in the copper foil with resin is preferably a material mainly composed of copper or a copper alloy. The thickness of the copper foil is preferably 35 μm or less, and more preferably within a range of 5 μm to 25 μm. From the viewpoint of production stability and handleability, the lower limit value of the thickness of the copper foil is preferably 5 μm. In addition, the copper foil may be a rolled copper foil or an electrolytic copper foil. Moreover, as copper foil, a commercially available copper foil can also be used.

The copper foil with resin can be prepared, for example, by sputtering metal on a resin film to form a seed layer, and then forming a copper layer by copper plating, for example, or by laminating a resin film and a copper foil by a method such as thermocompression bonding. . Furthermore, in order to form an adhesive layer on copper foil, the copper foil with resin can also be prepared by casting the coating liquid of the polyimide composition, drying to form a coating film, and then performing a desired heat treatment.

[Metal-clad laminate] (first form) A metal-clad laminate according to an embodiment of the present invention includes an insulating resin layer and a metal layer laminated on at least one surface of the insulating resin layer, and at least one layer of the insulating resin layer includes the resin film. In addition, the metal-clad laminate of the present embodiment may include any layers other than those described above.

(Second form) A metal-clad laminate according to another embodiment of the present invention includes, for example, an insulating resin layer, an adhesive layer laminated on at least one side of the insulating resin layer, and the insulating resin layer laminated with the adhesive layer interposed therebetween. In the so-called three-layer metal-clad laminate on the metal layer, the adhesive layer contains the resin film. In addition, the three-layer metal-clad laminate may include any layers other than those described above. The adhesive layer of the three-layer metal-clad laminate may be provided on one or both surfaces of the insulating resin layer, and the metal layer may be provided on one or both surfaces of the insulating resin layer via the adhesive layer. That is, the three-layer metal-clad laminate may be a single-sided metal-clad laminate or a double-sided metal-clad laminate. A single-sided FPC or a double-sided FPC can be manufactured by etching the metal layer or the like of the three-layer metal-clad laminate and performing wiring circuit processing.

The insulating resin layer in the three-layer metal-clad laminate is not particularly limited as long as it is composed of a resin having electrical insulating properties, and examples thereof include polyimide, epoxy resin, phenol resin, polyethylene, and polypropylene. , polytetrafluoroethylene, silicone, ethylene-tetrafluoroethylene copolymer (ethylene tetrafluoroethylene, ETFE), etc., preferably including polyimide. The polyimide layer constituting the insulating resin layer may be a single layer or multiple layers, and preferably includes a non-thermoplastic polyimide layer.

The thickness of the insulating resin layer in the three-layer metal-clad laminate is, for example, preferably in the range of 1 μm to 125 μm, and more preferably in the range of 5 μm to 100 μm. If the thickness of the insulating resin layer is less than the lower limit value, problems such as insufficient electrical insulating properties cannot be ensured in some cases. On the other hand, when the thickness of the insulating resin layer exceeds the upper limit, the metal-clad laminate is liable to warp and other defects.

The thickness of the adhesive layer in the three-layer metal-clad laminate is, for example, preferably in the range of 0.1 μm to 125 μm, and more preferably in the range of 0.3 μm to 100 μm. In the three-layer metal-clad laminate of the present embodiment, if the thickness of the adhesive layer is less than the lower limit value, problems such as insufficient adhesiveness cannot be ensured in some cases. On the other hand, when the thickness of the adhesive layer exceeds the upper limit, problems such as a decrease in dimensional stability may occur. In addition, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent of the entire insulating layer as a laminate of the insulating resin layer and the adhesive layer, the thickness of the adhesive layer is preferably 3 μm or more . In addition, the ratio of the thickness of the insulating resin layer to the thickness of the adhesive layer (thickness of the insulating resin layer/thickness of the adhesive layer) is, for example, preferably in the range of 0.1 to 3.0, more preferably in the range of 0.15 to 2.0. By setting it as such a ratio, the warpage of a three-layer metal-clad laminate can be suppressed. In addition, the insulating resin layer may contain a filler as needed. Examples of fillers include silicon dioxide, aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, aluminum fluoride, calcium fluoride, metal salts of organic phosphinic acid, and the like. These can be used alone or in combination of two or more.

[circuit board] The circuit board of the embodiment of the present invention is obtained by performing wiring processing on the metal layer of the metal-clad laminate of any of the above-described embodiments. A circuit board such as an FPC can be manufactured by processing one or more metal layers of the metal-clad laminate into a pattern by a conventional method to form a wiring layer (conductor circuit layer). In addition, the circuit board may include a cover film covering the wiring layer.

[Example] An Example is shown below, and the characteristic of this invention is demonstrated more concretely. However, the scope of the present invention is not limited to the Examples. In addition, in the following examples, unless otherwise specified, various measurements and evaluations were performed based on the following.

[Measurement of weight average molecular weight (Mw) of polyimide] The weight-average molecular weight was measured by a gel permeation chromatograph (manufactured by TOSOH Co., Ltd., trade name: HLC-8220GPC). Polystyrene was used as a standard material, and tetrahydrofuran (THF) was used as a developing solvent.

[Measurement of storage elastic coefficient] The measurement was performed using a dynamic viscoelasticity measuring apparatus (DMA: TA Instruments, trade name: RSA-G2).

[Evaluation of Dielectric Properties] Using a vector network analyzer (manufactured by Agilent, trade name: vector network analyzer E8363C) and SPDR resonator, the polyimide film (hardened polyimide film) was placed under a temperature: 23°C, humidity : After standing under the condition of 50%RH for 24 hours, the relative permittivity (ε) and the dielectric loss tangent (Tanδ) at a frequency of 10 GHz were measured.

[Glass transition temperature (Tg)] The adhesive tablet pressed under the conditions of temperature: 160°C, pressure: 3.5 MPa, and time: 60 minutes was cut into test pieces with a size of 5 mm × 20 mm, and a dynamic viscoelasticity measuring device (DMA: TA instrument ( TA Instrument), trade name: RSA-G2), measured from 30°C to 200°C at a temperature increase rate of 4°C/min and a frequency of 11 Hz, and the temperature at which the change in elastic modulus (tanδ) became the largest was defined as the glass transition temperature .

[tensile elastic coefficient and maximum elongation] A tensile test was performed at 50 mm/min on a test piece (width: 12.7 mm, length: 127 mm) of the resin film using a tension tester (Tensilon manufactured by Orientec). , and obtain the tensile elastic modulus and maximum elongation at 25°C.

[Solder heat resistance test (dry)] The single copper foil of the double-sided copper-clad laminate (manufactured by NIPPON STEEL Chemical & Material, trade name: Espanex MB12-25-12UEG) was etched and removed, and the other The copper foil surface and the adhesive sheet were laminated so as to be sandwiched between the copper foils, and were pressed under the conditions of temperature: 160° C., pressure: 3.5 MPa, and time: 60 minutes. After drying the test piece with the copper foil at 135°C/60 minutes, it was immersed in a solder bath set to each evaluation temperature from 260°C in units of 10°C to 300°C for 10 seconds, and the adhesion state was observed. , and confirm whether there are any defects such as foaming, swelling, and peeling. As a judgment, when no defect was confirmed at 280° C., it was set as ○ (good), and when a defect was confirmed, it was set as × (defect).

[Solder heat resistance test (moisture absorption)] The single-sided copper foil of the double-sided copper-clad laminate (manufactured by NIPPON STEEL Chemical & Material, trade name: Espanex MB12-25-12UEG) was removed by etching, and the The other copper foil surface and the adhesive sheet were laminated so as to be sandwiched between the copper foils, and were pressed under the conditions of temperature: 160° C., pressure: 3.5 MPa, and time: 60 minutes. The copper foil-coated test piece was left to stand at 40°C, relative humidity: 90% RH for 72 hours, and then immersed for 10 seconds in a solder bath set to each evaluation temperature from 240°C to 300°C in units of 10°C The adhesive state was observed, and the presence or absence of defects such as foaming, swelling, and peeling was confirmed. As a judgment, when no defect was confirmed at 260° C., it was set as ○ (good), and when a defect was confirmed, it was set as × (defect).

[Measurement of peel strength] Cut a double-sided copper clad laminate (manufactured by NIPPON STEEL Chemical & Material, trade name: Espanex MB12-25-12UEG) into width: 50 mm, length: 100 After mm, the adhesive sheet was placed on the copper foil side of the sample from which the copper foil on one side was removed by etching, and a polyimide film (Toray-Dupont Co., Ltd.) was laminated on the adhesive sheet. Manufactured, trade name: Kapton 50EN-S), and pressed under the conditions of temperature: 160° C., pressure: 3.5 MPa, and time: 60 minutes to prepare a laminate. The laminate was cut into a width of 5 mm to prepare a test piece, and a tensile tester (manufactured by Toyo Seiki Co., Ltd., trade name: Strograph VE) was used to extend the test piece in the 180° direction. The tensile strength was performed at a speed of 50 mm/min, and the peeling strength between the adhesive layer and the copper foil at this time was measured and used as the peeling strength.

[Evaluation method of film retention] The adhesive sheet was cut into a test piece having a width of 20 mm and a length of 20 mm, and was folded so as to form a crease along a diagonal line, and then opened, and the state of the film was observed. At this time, the case where the test piece did not have cracks even after being opened with a fold was made "good", and the case where a part of the test piece was cracked was made "unacceptable".

[Evaluation method of film defects] The polyimide varnish was applied to one side of the release-treated PET film, dried at 100° C. for 5 minutes, and then dried at 120° C. for 10 minutes, and the state of the film after peeling was observed. At this time, a film that did not originate from aggregates or due to poor solubility of the elastomer resin (drag marks) or the like was set as "good", and a film with interruption was set as "unacceptable".

[acid value] The acid value is the mg of potassium hydroxide (KOH) required to neutralize 1 g of the sample. It is measured, for example, by the following method. First, a sample is accurately weighed and placed in a 250 mL flask, 50 mL of ethanol or an equal volume mixture of ethanol and ether is added, heated to dissolve, and 0.1 N hydrogen is used while shaking and mixing if necessary. Titrate with potassium oxide solution (indicator: phenolphthalein). The end point of the titration was the point at which the light red color of the liquid continued for 30 seconds. Then, a blank test was performed by the same method for correction, and the value of an acid value was calculated|required by the following formula. Acid value = [consumption of 0.1 N potassium hydroxide solution (mL) × 5.611]/[sample amount (g)]

The abbreviations used in this example represent the following compounds. BTDA: 3,3',4,4'-benzophenone tetracarboxylic dianhydride DDA: Product name: PRIAMINE 1075 manufactured by Croda Japan Co., Ltd. by distillation and purification (component a: 99.2% by weight, component b: 0%, component c: 0.8%, Amine value: 210 mgKOH/g) N-12: Dodecanedioic acid dihydrazine NMP: N-methyl-2-pyrrolidone Elastomer resin 1: manufactured by KRATON, trade name: A1535HU (hydrogenated polystyrene elastomer resin, styrene unit content ratio of 58% by weight, specific gravity: 0.96, no acid value) Elastomer resin 2: manufactured by KRATON, trade name: G1652MU (hydrogenated polystyrene elastomer resin, styrene unit content ratio of 30% by weight, specific gravity: 0.91, no acid value) Elastomer resin 3: manufactured by KRATON, trade name: G1726VS (hydrogenated polystyrene elastomer resin, styrene unit content ratio of 30% by weight, specific gravity: 0.91, no acid value) Elastomer resin 4: manufactured by KRATON, trade name: G1645VS (hydrogenated polystyrene elastomer resin, styrene unit content: 13% by weight, specific gravity: 0.89, no acid value) Elastomer resin 5: manufactured by KRATON, trade name: FG1901GT (hydrogenated polystyrene elastomer resin, styrene unit content ratio: 30% by weight, specific gravity: 0.91, acid value: 10 mgKOH/g) Elastomer resin 6: manufactured by Asahi Kasei Corporation, trade name: Tuftec M1913 (hydrogenated polystyrene elastomer resin, styrene unit content ratio: 30% by weight, specific gravity: 0.91, acid value: 11 mgKOH/g) Elastomer resin 7: manufactured by Asahi Kasei Corporation, trade name: Tuftec M1943 (hydrogenated polystyrene elastomer resin, styrene unit content ratio: 20% by weight, specific gravity: 0.91, acid value: 11 mgKOH/g) In addition, in the said DDA, "%" of a component, b component, and c component means the area percentage of the chromatogram in GPC measurement. In addition, the molecular weight of DDA was calculated by the following formula (1). Molecular weight=56.1×2×1000/amine value･･･（1）

(Synthesis Example 1) A 1000 ml separable flask was charged with 55.51 g of BTDA (0.1721 mol), 94.49 g of DDA (0.1735 mol), 210 g of NMP and 140 g of xylene, and mixed well at 40°C for 1 hour , to prepare a polyamide solution. The polyimide solution was heated to 190°C, heated and stirred for 10 hours, and 125 g of xylene was added to prepare an imidized polyimide solution 1 (solid content: 31% by weight, weight average Molecular weight: 80,900, thermoplastic polyimide).

[Example 1] 1.12 g of N-12 and 7.8 g of Elastomer Resin 1 were prepared in 100 g of the polyimide solution 1 prepared in Synthesis Example 1, and xylene was added to dilute and stir so that the solid content was 27% by weight. Thus, a polyimide varnish 1a was prepared.

[Example 2 to Example 8] Polyimide varnish 2a was prepared in the same manner as in Example 1, except that Elastomer Resin 1, Elastomer Resin 2, Elastomer Resin 3, Elastomer Resin 4, and Elastomer Resin 5 were used and the compounding amounts were changed as shown in Table 1. ~ Polyimide Varnish 8a.

Comparative Example 1, Comparative Example 2 A polyimide varnish was prepared in the same manner as in Example 1, except that elastomer resin 6 and elastomer resin 7 were used, the compounding amount was changed as shown in Table 1, and the solid content concentration of the polyimide varnish was set to 31% by weight. 9a. Polyimide varnish 10a.

Comparative Example 3 A polyimide varnish 11a was prepared in the same manner as in Example 1, except that the elastomer was not used and the solid content concentration of the polyimide varnish was 31% by weight.

The formulations of Examples 1 to 8 and Comparative Examples 1 to 3 are shown in Tables 1 and 2.

[Table 1] Polyimide Varnish Example Comparative example 1 2 3 4 5 6 7 8 1 2 3 type 1a 2a 3a 4a 5a 6a 7a 8a 9a 10a 11a Polyimide solution 1 [g] 100 100 100 100 100 100 100 100 100 100 100 A Solid content of polyimide solution 1 [g] 31 31 31 31 31 31 31 31 31 31 31 cross-linking agent N-12 [g] 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 1.12 B Elastomer resin 1 [g] 7.8 15.5 23.3 Elastomer resin 2 [g] 7.8 15.5 Elastomer resin 3 [g] 7.8 Elastomer resin 4 [g] 7.8 Elastomer resin 5 [g] 7.8 Elastomer resin 6 [g] 6.2 Elastomer resin 7 [g] 6.2 solvent Xylene [g] 36.7 49.2 61.7 36.7 49.2 36.7 36.7 36.7 15.9 15.9 0.0 NMP [g] 2.1 10.5 19.0 2.1 10.5 2.1 2.1 2.1 0.4 0.4 1.3 Solid content concentration [wt%] 27 27 27 27 27 27 27 27 31 31 31

[Table 2] Polyimide Varnish Example Comparative example 1 2 3 4 5 6 7 8 1 2 3 type 1a 2a 3a 4a 5a 6a 7a 8a 9a 10a 11a B/(A+B) [wt%] 20.1 33.3 42.9 20.1 33.3 20.1 20.1 20.1 16.7 16.7 0.0 B/(A+B) [vol%] 23.0 37.5 37.5 24.0 38.7 24.0 24.4 24.0 20.4 20.4 0.0 Content [weight part] of B component with respect to A component 100 weight part 25.2 50.0 75.2 25.2 50.0 25.2 25.2 25.2 20.0 20.0 0.0 Content of component B relative to 100 parts by volume of component A [volume parts] 29.9 59.9 89.8 31.6 63.2 31.6 32.3 31.6 25.6 25.6 0.0

[Example 9] The polyimide varnish 1a prepared in Example 1 was applied to one side of a release-treated PET film, dried at 100° C. for 5 minutes, dried at 120° C. for 10 minutes, and peeled, thereby preparing the next Tablet 1b (thickness: 25 μm). Next, various evaluation results of the tablet 1b are as follows. Relative permittivity: 2.5, dielectric loss tangent: 0.0018, tensile modulus: 0.3 GPa, maximum elongation: 136%, Tg: 41°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.5 kN/m, film defect: good

[Example 10] The adhesive sheet 2b was prepared in the same manner as in Example 9 using the polyimide varnish 2a. Next, various evaluation results of the tablet 2b are as follows. Relative permittivity: 2.5, dielectric loss tangent: 0.0015, tensile elastic modulus: 0.3 GPa, maximum elongation: 195%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m, film defect: good

[Example 11] Using the polyimide varnish 3a, the adhesive sheet 3b was prepared in the same manner as in Example 9. Next, various evaluation results of the tablet 3b are as follows. Relative permittivity: 2.5, dielectric loss tangent: 0.0013, tensile modulus: 0.3 GPa, maximum elongation: 230%, Tg: 42°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.3 kN/m, film defect: good

[Example 12] Using the polyimide varnish 4a, in the same manner as in Example 9, an adhesive sheet 4b was prepared. Next, various evaluation results of the tablet 4b are as follows. Relative permittivity: 2.6, dielectric loss tangent: 0.0018, tensile modulus: 0.4 GPa, maximum elongation: 118%, Tg: 40°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.5 kN/m, film defect: good

[Example 13] The adhesive sheet 5b was prepared in the same manner as in Example 9 using the polyimide varnish 5a. Next, various evaluation results of the tablet 5b are as follows. Relative permittivity: 2.8, dielectric loss tangent: 0.0017, tensile elastic modulus: 0.3 GPa, maximum elongation: 144%, Tg: 40°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.6 kN/m, film defect: good

[Example 14] Using the polyimide varnish 6a, the adhesive sheet 6b was prepared in the same manner as in Example 9. Next, various evaluation results of the tablet 6b are as follows. Relative permittivity: 2.6, dielectric loss tangent: 0.0018, tensile modulus: 0.3 GPa, maximum elongation: 103%, Tg: 42°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m, film defect: good

[Example 15] An adhesive sheet 7b was prepared in the same manner as in Example 9 using the polyimide varnish 7a. Next, various evaluation results of the tablet 7b are as follows. Relative permittivity: 2.6, dielectric loss tangent: 0.0020, tensile modulus: 0.2 GPa, maximum elongation: 103%, Tg: 41°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m, film defect: good

[Example 16] Using the polyimide varnish 8a, the adhesive sheet 8b was prepared in the same manner as in Example 9. Next, various evaluation results of the tablet 8b are as follows. Relative permittivity: 2.6, dielectric loss tangent: 0.0019, tensile modulus: 0.3 GPa, maximum elongation: 122%, Tg: 41°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.2 kN/m, film defect: good

Comparative Example 4 Using the polyimide varnish 9a, in the same manner as in Example 9, an adhesive sheet 9b was prepared. Next, various evaluation results of the tablet 9b are as follows. Relative permittivity: 2.8, dielectric loss tangent: 0.0022, tensile modulus: 0.3 GPa, maximum elongation: 201%, Tg: 43°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.6 kN/m, film defect: impossible

Comparative Example 5 The adhesive sheet 10b was prepared in the same manner as in Example 9 using the polyimide varnish 10a. Next, various evaluation results of the tablet 10b are as follows. Relative permittivity: 2.8, dielectric loss tangent: 0.0022, tensile modulus: 0.2 GPa, maximum elongation: 185%, Tg: 41°C, film retention: good, solder heat resistance test (dry): ○, Solder heat resistance test (moisture absorption): ○, peel strength: 1.4 kN/m, film defect: impossible

Comparative Example 6 The adhesive sheet 11b was prepared in the same manner as in Example 9 using the polyimide varnish 11a. Next, various evaluation results of the tablet 11b are as follows. Relative permittivity: 2.6, dielectric loss tangent: 0.0021, tensile modulus: 0.5 GPa, maximum elongation: 119%, Tg: 44°C, film retention: good, solder heat resistance test (dry): ×, Solder heat resistance test (moisture absorption): ×, peel strength: 1.0 kN/m, film defect: good

The above results are collectively shown in Table 3.

[table 3] then tablet Example Comparative example 9 10 11 12 13 14 15 16 4 5 6 type 1b 2b 3b 4b 5b 6b 7b 8b 9b 10b 11b Relative permittivity 2.5 2.5 2.5 2.6 2.8 2.6 2.6 2.6 2.8 2.8 2.6 dielectric loss tangent 0.0018 0.0015 0.0013 0.0018 0.0017 0.0018 0.0020 0.0019 0.0022 0.0022 0.0021 Tensile modulus of elasticity [GPa] 0.3 0.3 0.3 0.4 0.3 0.3 0.2 0.3 0.3 0.2 0.5 Maximum elongation [%] 136 195 230 118 144 103 103 122 201 185 119 Tg[℃] 41 43 42 40 40 42 41 41 43 41 44 membrane retention good good good good good good good good good good good Solder heat resistance test (dry) 〇 〇 〇 〇 〇 〇 〇 〇 〇 〇 × Solder heat resistance test (moisture absorption) 〇 〇 〇 〇 〇 〇 〇 〇 × 〇 × Peel strength [kN/m] 1.5 1.4 1.3 1.5 1.6 1.4 1.4 1.2 1.6 1.4 1.0 Membrane defects good good good good good good good good not possible not possible good

From Table 3, it was confirmed that compared with the adhesive sheet 9b and the adhesive sheet 10b of Comparative Example 4 and Comparative Example 5, elastomer resin 1, elastomer resin 2, elastomer resin 3, elastomer resin 4, elastic resin The dielectric loss tangents of the adhesive sheets 1 b to 8 b of Examples 9 to 16 of the bulk resin 5 were 0.0020 or less, high peel strength was obtained, and no film defects were present. From such results, it was confirmed that the adhesive sheet as the resin film of the present embodiment can be expected to reduce transmission loss in a high frequency band of, for example, about 10 GHz to 20 GHz, and to have excellent flexibility and film retention while maintaining flexibility. peel strength.

As shown in the above examples, by adding a hydrogenated polystyrene elastomer resin having an acid value of 10 mgKOH/g or less to polyimide using aliphatic diamine as a raw material, a clear improvement in dielectric properties can be seen. Furthermore, the improvement of peeling strength was also seen. Furthermore, it was confirmed that the adhesive sheet obtained in each Example maintained the shape as a film by using a hydrogenated polystyrene elastomer resin having an acid value of 10 mgKOH/g or less in a blending amount within a practical range.

From the results described above, it was confirmed that the resin film of the present embodiment can be suitably used as a material for circuit boards such as high-frequency compatible FPCs.

As mentioned above, although embodiment of this invention was described in detail for illustration purpose, this invention is not limited by the said embodiment, Various deformation|transformation is possible.

Claims (12)

A polyimide composition, containing the following (A) components and (B) components; (A) thermoplastic polyimide, and (B) a polystyrene elastomer resin having an acid value of 10 mgKOH/g or less, And content of the said (B) component is in the range of 10 weight part or more and 100 weight part or less with respect to 100 weight part of said (A) component. The polyimide composition according to claim 1, wherein the content ratio of the styrene unit in the component (B) is within a range of 10% by weight or more and 65% by weight or less. The polyimide composition according to claim 1 or claim 2, wherein the thermoplastic polyimide is obtained by reacting a tetracarboxylic anhydride component with a diamine component, and contains, relative to the diamine component, a More than 40 mol% of aliphatic diamines. The polyimide composition according to claim 3, wherein the aliphatic diamine is a dimer obtained by substituting the two terminal carboxylic acid groups of the dimer acid with primary aminomethyl groups or amine groups A dimer diamine composition with diamine as the main component. The polyimide composition according to claim 1 or claim 2, further comprising an amine-based compound having at least two primary amine groups as functional groups. A resin film comprising a thermoplastic resin layer, the resin film being characterized by, The thermoplastic resin layer contains the following (A) components and (B) components; (A) thermoplastic polyimide, and (B) a polystyrene elastomer resin having an acid value of 10 mgKOH/g or less, And content of the said (B) component is in the range of 10 weight part or more and 100 weight part or less with respect to 100 weight part of said (A) component. The resin film according to claim 6, wherein after the thermoplastic resin layer is conditioned for 24 hours under a constant temperature and humidity condition of 23° C. and 50% RH, the dielectric properties at 10 GHz are measured by a split dielectric resonator (SPDR). The electrical loss tangent (Tanδ) is 0.0020 or less. A laminated body comprising: a base material; and an adhesive layer laminated on at least one surface of the base material, wherein the laminated body is characterized by: The adhesive layer includes the resin film according to claim 6. A coverlay film comprising: a coverlay film material layer; and an adhesive layer laminated on the coverlay film material layer, wherein the coverlay film is characterized by: The adhesive layer includes the resin film according to claim 6. A copper foil with resin, which is formed by laminating an adhesive layer and copper foil, the copper foil with resin is characterized by: The adhesive layer includes the resin film according to claim 6. A metal-clad laminate comprising: an insulating resin layer; and a metal layer laminated on at least one surface of the insulating resin layer, wherein the metal-clad laminate is characterized by: At least one of the insulating resin layers includes the resin film as claimed in claim 6. A circuit board obtained by wiring the metal layer of the metal-clad laminate according to claim 11.